Detective maths quest: money

Quick answer

You can solve detective maths mysteries by using money to figure out clues, count coins, and budget for items – just like a real detective!

Learning outcome

By the end of this page, you will be able to use money to solve puzzles, count coins, and work out how much things cost – just like a detective!

• You can add up different coins to find the total value
• You can work out how much change you should get
• You can compare prices to find the best deal
• You can use charts and clues to solve money puzzles

Why this matters

Money is everywhere in the world around us – from the coins in your pocket to the prices on shop shelves. As a detective, you need to understand money to solve mysteries like how much a ticket costs or how many sweets you can buy. This detective maths helps you make smart choices, just like a detective!

How it works

When you're a detective, you look for clues and solve puzzles using maths. Here's how to use money to solve detective mysteries:

1. Look at the coins or prices you have
2. Add them up to find the total
3. Work out how much change you should get
4. Use charts or clues to compare prices
5. Solve the mystery with your maths!

Examples you can see

Let’s imagine you’re a detective and you find some clues at a shop. You need to figure out how much everything costs and how much change you get.

Example 1: Counting coins

You find 3 coins: 50p, 20p, and 5p. How much money do you have?

Add them up: 50p + 20p + 5p = 75p

Example 2: Working out change

You buy a comic for 60p and give the shopkeeper 1 pound (100p). How much change should you get?

100p – 60p = 40p

You should get 40p change.

Example 3: Comparing prices

You find two tickets for a football match. One costs 30p, the other costs 40p. Which one is cheaper?

The ticket that costs 30p is cheaper.

Try it as a mini adventure

You are a detective in a magical town where everything costs in coins. You must solve these clues to catch the thief who stole a treasure chest!

Step 1: Find the coins

You find a pile of coins: 20p, 10p, 5p, 2p, 1p. How much do they add up to?

20p + 10p + 5p + 2p + 1p = ?

Step 2: Buy a ticket

You need to buy a train ticket that costs 75p. You have 1 pound (100p). How much change will you get?

Step 3: Solve the mystery

You find a note that says: “The treasure is worth 100p more than the ticket.” How much is the treasure worth?

Common mistakes

• Mistake: Adding coins like 20p + 5p = 25p instead of 25p
  Why it happens: Mixing up the numbers or rushing through the sum
  Fix: Count carefully and use a number line or coins to help you
• Mistake: Thinking 100p – 75p = 25p instead of 25p
  Why it happens: Confusing subtraction with addition
  Fix: Use your fingers or a calculator to check
• Mistake: Comparing prices like 30p and 40p and thinking 40p is cheaper
  Why it happens: Not knowing which number is bigger
  Fix: Use a number line or count up from the smaller number

Parent and carer guide

As a parent or carer, you can help your child by:

1. Playing money games at home – like pretending to shop
2. Using real coins to practice adding up
3. Letting your child count out change when you go shopping
4. Looking at prices together and comparing them
5. Encouraging them to solve money puzzles or detective clues

Remember: It's okay to make mistakes – that's how we learn!

Practice questions

1. You have 10p, 5p, and 2p. How much do you have in total?
2. You buy a book for 45p and pay with 50p. How much change should you get?
3. Which is cheaper: 35p or 40p?
4. You have 50p and want to buy a toy that costs 30p. How much will you have left?
5. How much is 10p + 20p + 5p?

Answers

1. 17p
2. 5p
3. 35p
4. 20p
5. 35p

FAQ

How can I practice detective maths at home?

You can play pretend shop with your toys, count coins, or use a chart to compare prices. It's like being a detective every day!

Why do I need to know about money?

Money helps you buy things, save for what you want, and understand how much things cost. It’s a real-life skill that helps you make smart choices.

What if I get the wrong answer?

That’s okay! Making mistakes is part of learning. You can check your work or ask someone to help you.

Can I use a calculator for detective maths?

Yes, you can use a calculator to check your work, but it’s good to practice adding and subtracting in your head too!

How can I get better at solving money puzzles?

Practice with real coins, play games, and try to solve puzzles with friends or family. The more you do it, the better you get!